QUANTITATIVE-DETERMINATION OF POTENTIAL DISTRIBUTION IN STERN-GOUY DOUBLE-LAYER MODEL

A quantitative determination of the potential distribution in the Ster n-Gouy double-layer model for clay-water-electrolyte systems is presen ted. The surface potential, Stern potential, thickness of the Gouy dif fuse layer, and distribution of electrical potential can be computed b y knowing the required parameters, such as the cation exchange capacit y, specific surface area, electrolyte concentration, and valence, temp erature, and permittivity of the solvent (pore fluid). The factors inf luencing the potential distribution in the double layer are discussed. To demonstrate the applications of the Stern-Gouy model, two examples are presented. In the first example, the relationship between the dou ble-layer thicknesses and hydraulic conductivities of a natural soil p ermeated by different organic compounds is established. In the second example, the electric potential distributions of three natural clays a re presented. It is anticipated that the Stern-Gouy double-layer model will find broader applications in geotechnical and environmental engi neering practice as the principles and computation methods become more familiar to engineers.